Coding beyond the computational cutoff rate

Citation

Abstract

This thesis presents a collection of new codes, algorithms, and hardware, which can all be used to reduce the required energy per information bit to noise spectral density ratio on the Gaussian channel. First comes a feedback technique from an outer to an inner code. The basic idea is to perform a second maximum likelihood decoding operation of the inner code that incorporates side information. Next comes a new kind of algebraic outer code which we get from combining Reed Solomon codes with themselves. The most important results, however, deal with the construction of long constraint length Viterbi decoders. One chapter presents a hardware design of a constraint length 15, rate 1/6 decoder. The last chapter gives some results on the partitioning of a deBruijn graph which make the number of interconnections in the design physically realizable.